Keyboard perforator



E. S. LARSON KEYBOARD PERFORATOR May 19, 1959 2,887,158

2 Sheets-Sheet 1 Filed June 21, 1955 FIG.

ATTORNEY May 19, 1959 Filed June 21, 1955 E. S. LARSON KEYBOARD PERFORATOR 2 Sheets-Sheet 2 INVENTOR EDWARD S. LARSON (if m ATTORNEY United States Patent KEYBOARD PERFORATOR Application June 21, 1955, Serial No. 516,862 1 Claim. (Cl. 164-113) The present invention relates generally to perforating apparatus and more particularly to keyboard perforators for the perforation of indicia in a strip which may be used for the automatic control of a machine.

The present invention has for its main object the provision of an electromechanical clutch trip mechanism which will reduce the amount of force necessary to actuate the clutch mechanism.

A further object is to provide a differential contact mechanism which will prevent actuation of the clutch trip mechanism through inadvertent opening and closing of the control contacts.

Another object is to provide a simplified, positive acting trip mechanism which will reduce wear caused by friction of the moving parts.

The present invention is illustrated in a keyboard perforator similar to that disclosed in Patent No. 2,019,505, issued to A. H. Reiber on November 5, 1935. The keyboard perforator has a bank of keylevers similar to that of a typewriter. Each keylever is operatively positioned with respect to a group of selector elements. Depression of each of the keylevers operates the selector elements as to coincide with a predetermined permutation of punches to be operated. Also actuated by the depression of each keylever, is a universal trip-oh mechanism which controls the one cycle operation of a power driven means for operating the permutatively selected punches. Since the present invention is primarily concerned with an improved trip-ofi mechanism, only so much of the keyboard perforator as is necessary for understanding of the invention will be discussed. For the sake of clarity the reference numerals used for similar parts shall be the same as those of the aforementioned Reiber patent which is incorporated herein by reference.

A better understanding of the invention may be had from the following description taken in conjunction with the accompanying drawings wherein:

Fig. 1 is a partial perspective view of a keyboard perforator embodying the features of the present invention; Fig. 2 is an elevation showing the features of the present invention and the wiring diagram associated therewith when the clutch is latched; and I Fig. 3 is a detailed elevational view of the trip-ofic' mechanism after the clutch has been unlatched.

Referring now to the drawings wherein like reference numerals indicate the same parts throughout the several views, and more particularly to Fig. 1, there is shown a keyboard unit and a perforating unit indicated generallyas 11 and 12 which are mounted on a common base 13. The keyboard unit 11 comprises a plurality of keys 15 and keylevers 14 as well as a space bar and lever not shown. The power shaft 68 is driven from the gear 71' on the constantly rotating motor 69 and the gear 72 engaged therewith. Operation of the perforator 12 is powered by the rotation on the cam 42 through a combination friction and grab type clutch associated with the collar 85. A complete description of the function can be. found in the Reiber patent. Rotation of this collar and thereby the cam 42 is prevented by the stop lever 84- associated with one of the horizontal extensions 82 or 83 which are associated with the slots on the collar 85. The selection of a permutation of punches by the keylevers 14 and the actuation of the above-mentioned cycle of operation by the keylevers is fully treated in the aforementioned Reiber patent.

Refer now to Fig. 2 wherein the collar 85 is in its blocked position due to the cooperation of the stop extension 84 on a pivotally mounted lever 87 with the horizontal extension 83. A pivotally mounted latch 89 is engaged with a latch extension 88 of the lever 87 to prevent the lever 87 from being rotated counterclockwise (Fig. 2) by its spring 91. A nonrepeat lever 92 is pivotally mounted so that its latching shoulder 97 overlaps the stop extension 88. A nonrepeat lever spring 93 is positioned at one end of the lever 92 on an extension 21 of the latch lever 89 so as to urge the nonrepeat lever 92 to rotate in a clockwise direction when the lever 89 is caused to rotate in a clockwise direction. A cam extension 22 is rigidly mounted on the lever 87 in a position that the elongated portions of the collar 85 will contact the cam roller 23 and thereby cause the lever 87 to be rotated clockwise (Fig. 2) about its pivot point 24. A trip-off arm 26 is pivotally mounted at 27 with its free end associated with the latch lever 89. An electromagnet 28 is positioned beneath the trip-off arm 26 in such a manner that when it is energized, it will attract the arm 26 to rotate said arm 26 in a counterclockwise direction (Figs. 2 and 3) against the urging of the arm spring 29. It is apparent that as the arm 26 is rotated counterclockwise, the latch lever 89 will be rotated thereby in a clockwise direction to unlatch the blocking lever 87 leaving the collar 85 free to be rotated by friction clutch mentioned above. Rotation of the latch lever 89 compresses the nonrepeat spring 93 to urge the nonrepeat lever 92 in a clockwise direction (Figs. 2 and 3). As the collar 85 is rotated, its elongated portion will contact the cam roller 23 to rotate the blocking lever 87 clockwise (Figs. 2 and 3) to its blocking position where it is latched by the latching lever 89, if that lever has been allowed to return to its latching position, or by the shoulder 97 of the nonrepeat lever 92 in the event that latching lever 89 has not returned to its latching position.

Referring now to the circuit diagram shown as part of Fig.. 2,. it. is seen that the current is brought in from a' source of. power through line 7. If the power source is alternating current, a' rectifier 31 is connected into the line in order to ultimately supply direct current to the electromagnet 28. After going through the rectifier, the current passes through the current limiting resistor 32- and to the leaf, contact spring or spring conductor 34 of contact pair 57. It will be noted that while the circuit is open at leaf 34, a charge will be built up in the capacitors 46. A leaf, contact spring or spring conductor 36 is positioned to be moved into contact with the leaf 34 :3 by movement of the plunger rod 64, when the plunger rod 64 is operated by any keylever as described in the Reiber patent. When the contact pair 57 is closed the current will pass through line 37 to leaves 38 and 39 of contact 56 and then through line 41 to the electromagnet 28 to energize the magnet 28.

In order to insure rapid and positive actuation of the electromagnet 28, a high initial charge must be introduced into the magnet. It is for this purpose that the capacitors 46 are used in the circuit.

It should be noted that until the magnet 28 is energized, the resistor 44 is shunted out of the line. Positioned between the leaf 39 and the blocking lever 89 is a plunger 47. Plunger 47 is so positioned that clockwise rotation (Fig. 2) of the blocking lever 89 will cause the plunger 47 to move downward and thereby move the leaf 3.9 away from the leaf 38 to open contact 56 and put the resistor 44 into the circuit. The resistor 44 reduces the current flow to the magnet 28 to a holding Gurrent and permits a partial recharge of the capacitors 46 to thereby assure adequate build up for the subsequent operation regardless of time between keystrokes.

If an operator we to move the plunger rod 64 through operation of the keylever 14, only far enough to move leaf 36 into light contact with the leaf 34, there would be a tendency for the contact to be opened and closed by vibrations of the machine and cause undesirable repetitions of operation of the trip-off mechanism. To prevent this happening, a differential lever 48 is pivotally mounted at 49 with its insulated cam extension 51 supportin one end of the contact leaf 34 and urging leaf 34 upward while the magnet 28 is de-energized. An extension 52 of the blocking lever 89 is positioned with respect to a bifurcated portion 53 of the dilferential lever 48 in such a manner that rotation of the lever 89 will cause the differential lever 48 to be rotated in the opposite direction. Reference to Figs. 2 and 3 clearly illustrates that as a result of action of the differential lever, the plunger rod 64 will cause the contact 57 to be closed at a point A on Fig. 3 while the contact will not be opened until the gap 54 is closed so that the opening point is at B thereby eliminating the possibility of unintended repetition.

In operation, as illustrated in Figs. 2 and 3, the clutch trip-off mechanism is in the position illustrated in Fig. 2 when the key 15 and thereby the keylever 14 is operated. Operation of the keylever causes the plunger rod 64 to be moved upward according to the operation as set forth in the afore-mentioned Reiber patent. As the rod 64 moves upward, it moves the leaf 36 toward the leaf 34 to complete the circuit from line 7 through the contact 56 and line 4-1 to the electromagnet 28. The initial surge of current from the capacitors 46 actuates the electromagnet 28. Energization of the magnet 28 attracts the armature lever 26 to rotate it counterclockwise against the urging of its spring 27. As the armature lever 26 rotates, it contacts the blocking lever 89 causing lever 89 to be rotated clockwise. As a result of the lever 89 being rotated the following functions occur: the projection 88 of the blocking member 87 is unlatched so that the member 87 can be rotated counterclockwise by its spring 91 to unblock the collar 35; the plunger 47 is moved downward to open the contact 56 thereby putting the resistor 44 into the magnet circuit; the extension 21 of the lever 89 moves upward against the nonrepeat lever spring 93 to urge the nonrepeat lever 92 to be rotated clockwise so that it is conditioned to latch the blocking member 87 upon its return; and the extension 52 is moved upward against the upper bifurcation of the differential lever 43 to rotate lever 48 thereby moving the insulated cam portion 51 of the lever 48 away from the leaf 3.4, which is maintained in its tensioned position by the leaf 36, to create the gap 54 (Fig. 3). The trip-01f mechanism is now positioned as illustrated in Fig. 3.

Referring to Fig. l, unblocking the collar permits the friction clutch 75 to rotate the collar 85 into engagement with the positive clutch to rotate the sleeve 43 and the cam 42 and thereby actuate the perforating mechanism 12 as described in detail in the Reiber patent.

Referring again to Figs. 2 and 3, the positive clutch is engaged and rotates the sleeve 43 and therewith the collar 85 in a clockwise direction, the elongated portion of the collar 85 will contact the cam roller 23 causing the blocking lever 87 to be rotated clockwise past its blocking position where it will be latched in place by the cooperation of the shoulder 97 on the nonrepeat lever 92 and the extension 88 of lever 87. The blocking lever is then in position so its extension 84 will cooperate with the extension 31?, to prevent further rotation of the collar 85.

As the keylever is released, the plunger rod 64 travels downward. During the first portion of its downward movement (from point A to point B in Fig. 3) the contact 57 remains closed as both leaves return to their normal position. When the leaf 34 reaches its untensioned position the gap 54 is reduced to zero and further downward movement of the plunger rod 64 and leaf 36 therewith causes the contact 57 to open. With the breaking of the circuit the electromagnet 28 is deenergized allowing the armature lever 26 to be rotated clockwise by its spring 27. Rotation of the lever 26 permits the spring 94 to rotate the blocking lever 89 counterclockwise thereby causing the following operations: the nonrepeat lever 92 is rotated counterclockwise out of engagement with extension 88 as latching lever 89 is rotated into engagement with extension 88; lever 89 moves away from the plunger 47 to permit the leaf 39 to resume its untensioned position thereby closing the contact se to shunt out the resistor 44; and the extension 52 of the lever 89 is moved against the bottom bifurcation of the differential lever 48 to rotate the lever 48 clockwise about its pivot point 49 to thereby move the insulated cam portion 51 of the difierential lever 48 upwardly against the leaf 34 and move the leaf 34 to its tensioned position.

If the keylever is released so that the contact 57 is broken before the lever 87 is returned to its blocking position, it will, of course, be latched in position by the latching lever 89 rather than the nonrepeat lever 92 as previously described.

While the present invention has been described with reference to a specific illustration, it is of course understood that the invention is capable of embodiment in widely varied forms without departure from the spirit and scope of this invention.

What is claimed is:

The combination of a key controlled perforator having cam actuated punches, a blocking member for blocking rotation of said cam, and a latch member operable in normal position for holding said blocking member in position to block rotation of said cam, with a circuit including an electromagnet for moving said latch member out of normal position, and means for controlling the operation of said electromagnet comprising a power source, a contact means for connecting the power source to said electromagnet, a first spring conductor in said contact means normally biased to remain in a predetermined position, a second spring conductor also in said v contact means normally biased for movement toward the first spring conductor, means for moving said first spring conductor into engagement with said second spring conductor to close the circuit from the power source to the electromagnet, a pivotally mounted differential lever having one end positioned to engage the second spring conductor and having its other end bifurcated to provide. spaced surfaces for alternate engagement by opposite sides of said latch member when said latch member is in its normal and its out of normal positions, whereby said latch member in its normal position will cause the differential lever to restrain the second spring conductor against movement toward engagement with the first spring conductor but the latch member in its out of normal position will permit said second spring conductor to move into engagement with said first spring conductor through a part of the distance between the restrained position of the second spring conductor and the predetermined position of the first spring conductor, and means actuated by the keys for moving said second conductor to engage the first conductor while the first conductor is held by the differential lever.

References Cited in the file of this patent UNITED STATES PATENTS Mailloux Jan. 19, 1897 Murdock Sept. 9, 1924 Whittingham Sept. 19, 1933 Mills et a1 Apr. 11, 1944 Ahlberg Jan. 3, 1950 Forman Aug. 29, 1950 Anderson Aug. 19, 1952 FOREIGN PATENTS Germany Feb. 17, 1908 

